Ch. 20: Allergic Reaction Flashcards
allergic reaction
an exaggerated immune response.
allergen
sometimes the cause of the allergic reaction
anaphylaxis
a severe or life-threatening allergic reaction in which the blood vessels dilate, causing a drop in blood pressure, and the tissues lining the respiratory system swell, interfering with the airway.
Causes of allergic reactions
insects, foods, plants, medications, Dust, chemicals, soaps, makeup, latex
hives
red, itchy, possibly raised blotches on the skin that often result from allergic reactions
Signs and Symptoms of an allergic reaction
○ Signs and Symptoms:
• No way to predict exact course of reaction
□ patient’s airway may swell and close off in just a few minutes. Be prepared to manage the airway and to administer epinephrine if so advised by medical direction.
• skin:
• Itching
• Hives (may be localized—especially around an insect sting—or generalized over wide
areas of the body)
• Flushing (red skin)
• Swelling of the face (especially the eyes and lips), neck, hands, feet, or tongue
• Warm, tingling feeling in the face, mouth, chest, feet, and hands
• respiratory:
• Patient may report a feeling of tightness in the throat or chest
• Cough
• Rapid breathing
• Labored, noisy breathing
• Hoarseness, muffled voice, or loss of voice entirely
• Stridor (harsh, high-pitched sound during inspiration)
• Wheezing (audible without a stethoscope)
• cardiac:
• Increased heart rate
• Decreased blood pressure
• generalized Findings:
• Itchy, watery eyes
• Headache
• Runny nose
• Patient expresses a sense of impending doom
• signs and symptoms of shock:
• Altered mental status
• Flushed, dry skin or pale, cool, clammy skin
• Nausea or vomiting
Changes in vital signs: increased pulse, increased respirations, decreased blood pressure
Distinguishing anaphylaxis from Mild Allergic Reaction
To be considered a severe allergic reaction, or anaphylaxis, the patient must have either respiratory distress or signs and symptoms of shock.
Patient Assessment: Allergic Reaction to Anaphylaxis
○ Conduct the usual assessment sequence, as follows:
1. Perform the primary assessment and care for any immediately life-threatening problems with the patient’s airway, breathing, or circulation.
2. Perform a secondary assessment. Inquire about:
• History of allergies
• What the patient was exposed to
• How the patient was exposed (contact, ingestion, and so on) • What signs and symptoms the patient is having
• Progression (What happened first? Next? How rapidly?)
• Interventions (Has any care been provided? Has the patient taken any medication?)
3. Assess baseline vital signs, and get the remainder of the past medical history.
• Suspect an allergic reaction whenever the patient has come in contact with a substance that has caused an allergic reaction in the past; whenever the patient complains of itching, hives, or difficulty breathing (respiratory distress); or when the patient shows signs or symptoms of shock (hypoperfusion).
○ Table 20-1 lists specific signs and symptoms and their likely association with either a non-life-threatening allergic reaction or a life-threatening anaphylactic reaction.
○ Decision Points
• Is this an allergic reaction or anaphylaxis?
• Does it have the potential to become anaphylaxis?
Do I need to administer an epinephrine auto-injector?
Patient Care: Allergic Reaction or Anaphylaxis
- Manage the patient’s airway and breathing. Apply high-concentration oxygen through a nonrebreather mask if the patient is in distress or in some other way appears to be having an anaphylactic reaction. Mild allergic reactions do not require oxygen. If you are not sure, apply oxygen and reassess the patient later to see if it is still necessary. If the patient has or develops an altered mental status, open and maintain the patient’s airway. If the patient is not breathing adequately, provide artificial ventilations.
2. You may be able to assist the patient in administering an epinephrine auto-injector, or you may be allowed to carry auto-injectors on your ambulance. To find out if use of an
auto-injector is appropriate, consider each of the following:
• If the patient has come in contact with a substance that caused an allergic reaction in the past, and if the patient has respiratory distress or exhibits signs and symptoms of shock, and if the patient has a prescribed epinephrine auto-injector (or if your proto- cols allow you to carry and use epinephrine auto-injectors), then contact medical direction and, if so ordered, assist the patient with his prescribed auto-injector or administer epinephrine from an auto-injector you carry on the ambulance (Scan 20-1). Record the administration of the epinephrine auto-injector. Transport. Reassess 2 minutes after epinephrine administration and record reassessment findings.
• If the patient has come in contact with a substance that caused an allergic reaction in the past, but the patient is not wheezing or showing signs of respiratory distress or shock (hypoperfusion), then continue with the assessment. Consult medical direction; if the patient has an epinephrine auto-injector and if medical direction so orders, administer epinephrine. Some patients have histories of very rapid onset of severe symptoms, so the physician may wish you to give the medication even though the patient does not appear to need it.
• If the patient has come in contact with a substance that caused an allergic reaction in the past, and if the patient complains of respiratory distress or exhibits signs and symptoms of shock, but the patient does not have a prescribed epinephrine auto- injector available or has never had one prescribed, and your protocols do not allow you to carry and use epinephrine auto-injectors, then perform care for shock and transport the patient immediately.
If the patient meets the criteria just listed but does not have an epinephrine auto-injector and your protocols do not allow you to carry and use one, consider requesting an ALS intercept. Paramedics carry and can administer epinephrine.
epinephrine
a hormone produced by the body. As a medication, it constricts blood vessels and dilates respiratory passages and is used to relieve severe allergic reactions.
Ana-Kit or EpiPen
To give epinephrine
must be in anaphylaxis and have a prescribed epi-pen
epinephrine dose
adult: 0.3 mg child: 0.15 mg
